Exposure apparatus

Abstract

An exposure apparatus for exposing a wafer to a pattern of a mask is disclosed. The apparatus includes a metal-vapor laser for supplying light and an optical arrangement for directing, through the mask, the light supplied by the laser to the wafer.

What is claimed is: 
     
       1. An exposure apparatus for exposing a wafer to a pattern of a mask, said apparatus comprising: a metal-vapor laser for supplying a laser beam; and   an optical arrangement for directing, through the mask, the laser beam supplied by said laser to the wafer;   wherein said optical arrangement comprises a harmonic generator for transforming the laser beam directed to the mask into a harmonic beam and for exposing the wafer to the pattern of the mask and printing the pattern of the mask onto the wafer.   
     
     
       2. An apparatus according to claim 1, wherein said laser comprises a copper-vapor laser and wherein said harmonic generator transforms the laser beam from said copper-vapor laser into a second harmonic beam, the transformed second harmonic beam being directed to the wafer. 
     
     
       3. An apparatus according to claim 1, further comprising monitoring means for monitoring the intensity of the harmonic beam and adjusting means for adjusting the inclination of said harmonic generator in response to an output signal from said monitoring means. 
     
     
       4. An apparatus according to claim 1, wherein said optical arrangement further comprises a projection optical system for projecting, upon the wafer, the pattern of the mask illuminated by the harmonic beam. 
     
     
       5. An apparatus according to claim 4, wherein said projection optical system comprises a single glass material. 
     
     
       6. An apparatus according to claim 1, wherein said optical arrangement further comprises: a first lens system for reducing the diameter of the laser beam from said laser and for directing the reduced beam to said harmonic generator;   a second lens system for enlarging the diameter of the harmonic beam from said harmonic generator; and   an illumination lens system for illuminating the mask by the harmonic beam enlarged by said second lens system.   
     
     
       7. An apparatus according to claim 6, further comprising means for modulating the intensity of the laser beam directed to said harmonic generator. 
     
     
       8. A projection exposure apparatus, comprising: a metal-vapor laser for emitting a laser beam;   a mask stage for supporting a mask;   a wafer stage for supporting a wafer;   illumination means for illuminating the mask with the laser beam emitted from said laser, said illumination means comprising a harmonic generator for transforming the laser beam into a harmonic beam being directed to the mask; and   a projection lens system for projecting, upon the wafer, a pattern of the mask illuminated by the harmonic beam, for printing the pattern of the mask on the wafer.   
     
     
       9. An apparatus according to claim 8, wherein said laser comprises a copper-vapor laser and wherein said harmonic generator produces a second harmonic beam for being directed to the mask. 
     
     
       10. An apparatus according to claim 9, wherein said laser emits a laser beam having a wavelength of approximately 510 nm. 
     
     
       11. An apparatus according to claim 9, wherein said laser emits a laser beam having a wavelength of approximately 578 nm. 
     
     
       12. An apparatus according to claim 9, wherein said harmonic generator comprises an electrooptic crystal. 
     
     
       13. An apparatus according to claim 12, wherein said crystal comprises β-BaB 2  O 4 . 
     
     
       14. A projection exposure apparatus for the manufacture of semiconductor devices, comprising: a copper-vapor laser for emitting a first harmonic laser beam;   a mask stage for supporting a mask;   a wafer stage for supporting a wafer;   illumination means comprising a second harmonic generator for transforming the laser beam emitted from said laser into a second harmonic beam for illuminating the mask; and   a reduction projection lens system provided between said mask and wafer stages, for projecting a circuit pattern of the mask upon the wafer for printing the circuit pattern of the mask onto the wafer.   
     
     
       15. An exposure method, comprising the steps of: emitting a laser beam from a metal-vapor laser;   transforming the laser beam into a harmonic beam; and   exposing a workpiece to the harmonic beam for printing a predetermined pattern on the workpiece.   
     
     
       16. A method according to claim 15, wherein said step of emitting a lasser beam comprises emitting the laser beam from a copper-vapor laser. 
     
     
       17. A method according to claim 16, wherein said step of transforming the lasser beam comprises transforming the laser beam into a second harmonic beam. 
     
     
       18. A method according to claim 17, wherein said step of exposing the workpiece to the harmonic beam comprises expanding the harmonic beam, illuminating a predetermined circuit pattern of a mask with the expanded beam and projecting the illuminated circuit pattern of the mask onto the workpiece by a projection lens system.